Protective film forming film, composite sheet for protective film forming, method for manufacturing a semiconductor device, and use of protective film forming film

Abstract

To provide a protective film forming film having high stability when it is stored at room temperature, a protective film forming composite sheet having the protective film forming film, and a method for manufacturing a semiconductor device using the protective film forming film or the protective film forming composite sheet.SOLUTION: In a thermosetting protective film forming film 13, when a test piece of the protective film forming film 13 is heated from 23°C to 300°C at a temperature increase rate of 10°C / min by differential scanning calorimetry, an exothermic onset temperature is 160°C or higher. A protective film forming composite sheet 101 includes a support sheet 10, and the protective film forming film 13 provided on one surface 10a of a support sheet 10.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a protective film-forming film, a composite sheet for forming a protective film, a method for manufacturing a semiconductor device, and the use of a protective film-forming film. [Background technology]

[0002] Some semiconductor wafers have circuits formed on one side (the circuit side), and further have protruding electrodes such as bumps on that side (the circuit side). Such semiconductor wafers are divided into semiconductor chips, and their protruding electrodes are connected to connection pads on a circuit board, thereby mounting them on the circuit board. In such semiconductor wafers and semiconductor chips, the side opposite the circuit surface (the back surface) is sometimes protected with a protective film to suppress damage such as crack formation.

[0003] To form such a protective film, a protective film-forming film is attached to the back surface of the semiconductor wafer. The protective film-forming film is laminated on a support sheet and may be used as a composite sheet for protective film formation, or it may be used without being laminated on a support sheet. Subsequently, the semiconductor wafer with the protective film-forming film on its back surface (semiconductor wafer with protective film-forming film) is processed through various subsequent processes to become a semiconductor chip with a protective film on its back surface (semiconductor chip with protective film). After being picked up, such a semiconductor chip with a protective film is mounted on the circuit side of a substrate to constitute a semiconductor device. The protective film-forming film forms a protective film, for example, by curing.

[0004] The protective film-forming film is required to be able to adequately protect the back surface of the semiconductor chip in its final protective film state, thereby suppressing so-called chipping, which occurs in minute defects on the semiconductor chip. A protective film-forming film that meets this objective has been disclosed (see Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 4897979 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, among protective film-forming films, thermosetting protective film-forming films that harden upon heating are generally recommended to be stored in a refrigerator from immediately after manufacture until use. This is because if protective film-forming films are stored without refrigeration, their stability is low, and some of the components necessary for the thermosetting properties to manifest may react during storage, potentially causing the protective film-forming film to not function properly when actually used. However, refrigerated storage is more expensive than room temperature storage, and handling the protective film-forming films is also more complicated. Therefore, in recent years, there has been a demand for protective film-forming films that can be used without problems even when stored at room temperature. In contrast, the protective film-forming film disclosed in Patent Document 1 has low stability when stored at room temperature.

[0007] The present invention aims to provide a protective film-forming film that has high stability when stored at room temperature, a composite sheet for forming a protective film equipped with the protective film-forming film, and a method for manufacturing a semiconductor device using the protective film-forming film or the composite sheet for forming a protective film. [Means for solving the problem]

[0008] To solve the above problems, the present invention adopts the following configuration. [1] A thermosetting protective film, wherein, by differential scanning calorimetry, when a test specimen of the protective film is heated from 23°C to 300°C at a heating rate of 10°C / min, the exothermic onset temperature is 160°C or higher. [2] The protective film forming film according to [1], wherein the protective film forming film contains a filler (D), and the ratio of the content of the filler (D) to the total mass of the protective film forming film in the protective film forming film is 63% by mass or less. [3] The protective film forming film according to [1] or [2], wherein the protective film forming film contains a filler (D), and the ratio of the content of the filler (D) to the total mass of the protective film forming film in the protective film forming film is 50% by mass or more. [4]. A protective film-forming film according to any one of [1] to [3], wherein the heat generation onset temperature is 170°C or higher. [5] A composite sheet for forming a protective film, comprising a support sheet and a protective film forming film provided on one surface of the support sheet, wherein the protective film forming film is the protective film forming film described in any one of [1] to [4].

[0009] [6] A method for manufacturing a semiconductor device, the manufacturing method comprising: an attachment step of attaching one side of a protective film forming film described in any one of [1] to [4], or the exposed side of a protective film forming film in a protective film forming composite sheet described in [5], to the back surface of a semiconductor wafer; a heat curing step after the attachment step of heat curing the protective film forming film to form a protective film; a printing step after the heat curing step of, if the protective film forming composite sheet is used, laser printing on the side of the protective film in the protective film forming composite sheet that is on the support sheet side, or if the protective film forming film that is not part of the protective film forming composite sheet is used, laser printing on the other side of the protective film; and if the protective film forming composite sheet is used after the printing step of laser printing on the protective film forming composite sheet A method for manufacturing a semiconductor device, comprising: a processing step of producing a semiconductor chip with a protective film, comprising: dividing the semiconductor wafer into semiconductor chips on the support sheet, cutting the protective film along the division points of the semiconductor wafer, and, if a protective film forming film that does not constitute the protective film forming composite sheet is used, attaching a dicing sheet to the other side of the protective film, dividing the semiconductor wafer into semiconductor chips on the dicing sheet, and cutting the protective film along the division points of the semiconductor wafer, thereby producing a semiconductor chip with a protective film comprising the semiconductor chip and the cut protective film provided on the back surface of the semiconductor chip; and a pickup step of picking up the semiconductor chip with a protective film after the processing step by pulling it away from the dicing sheet or support sheet. [7] The method for manufacturing a semiconductor device according to [6], wherein the composite sheet for forming a protective film, or the protective film forming film that does not constitute the composite sheet for forming a protective film, is stored at room temperature for 30 days before being used in the bonding step.

[0010] [8] Use of a protective film forming film for attaching to the back surface of a semiconductor wafer opposite to the circuit surface, and for forming a protective film on the back surface of a semiconductor chip obtained by dividing the semiconductor wafer, wherein the protective film forming film is the protective film forming film described in any one of [1] to [4]. [9]. Use of the protective film forming film according to [8], wherein the protective film forming film is attached to the back surface of the semiconductor wafer after being stored at room temperature for 30 days.

Effects of the Invention

[0011] According to the present invention, there are provided a protective film forming film having high stability when stored at room temperature, a composite sheet for forming a protective film including the protective film forming film, and a method for manufacturing a semiconductor device using the protective film forming film or the composite sheet for forming a protective film.

Brief Description of the Drawings

[0012] [Figure 1] It is a cross-sectional view schematically showing an example of a protective film forming film according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 3] It is a cross-sectional view schematically showing another example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 4] It is a cross-sectional view for schematically explaining an example of a method for manufacturing a semiconductor device according to an embodiment of the present invention. [Figure 5] It is a cross-sectional view for schematically explaining another example of a method for manufacturing a semiconductor device according to an embodiment of the present invention. <�

Modes for Carrying Out the Invention

[0013] ◇Protective Film Forming Film The protective film forming film according to an embodiment of the present invention is a thermosetting protective film forming film, and the heat generation start temperature (which may be simply referred to as "heat generation start temperature" in this specification) when the test piece of the protective film forming film is heated from 23°C to 300°C at a heating rate of 10°C / min by differential scanning calorimetry (DSC) is 160°C or higher. The protective film forming film of this embodiment can form a composite sheet for forming a protective film, for example, by laminating it with a support sheet as described later.

[0014] When measuring the heat generation start temperature by the DSC method using a test piece to be fabricated hereinafter, the protective film forming film of the present embodiment has the property that the heat generation start temperature is 160°C or higher. The protective film forming film of the present embodiment having such a property has high stability when stored at normal temperature. In this specification, "normal temperature" means a temperature that is not particularly cooled or heated, that is, an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

[0015] By using the protective film forming film of the present embodiment or a composite sheet for forming a protective film provided with the same, a semiconductor chip with a protective film forming film including a semiconductor chip and a protective film forming film provided on the back surface of the semiconductor chip can be manufactured. Further, from the semiconductor chip with a protective film forming film, a semiconductor chip with a protective film including a semiconductor chip and a protective film provided on the back surface of the semiconductor chip can be manufactured. Further, a semiconductor device can be manufactured using the semiconductor chip with a protective film.

[0016] On one surface of a semiconductor wafer, a circuit is formed. In this specification, the surface of the semiconductor wafer on which the circuit is formed in this way is referred to as the "circuit surface". And the surface on the opposite side of the circuit surface of the semiconductor wafer is referred to as the "back surface". The semiconductor wafer is divided by means such as dicing to become semiconductor chips. In this specification, similar to the case of a semiconductor wafer, the surface of the semiconductor chip on which the circuit is formed is referred to as the "circuit surface", and the surface on the opposite side of the circuit surface of the semiconductor chip is referred to as the "back surface". It is preferable that protruding electrodes such as bumps and pillars are provided on both the circuit surface of the semiconductor wafer and the circuit surface of the semiconductor chip. The protruding electrode is preferably composed of solder.

[0017] Furthermore, a semiconductor device can be manufactured by using the semiconductor chip with a protective film. In this specification, "semiconductor device" refers to a semiconductor chip with a protective film, which is flip-chip connected to a connection pad on a circuit board at a protruding electrode on the circuit surface of the semiconductor chip.

[0018] The protective film-forming film of this embodiment is thermosetting and functions as a protective film through its thermal curing.

[0019] A protective film-forming film at room temperature is heated to a temperature above room temperature, and then cooled back to room temperature to obtain a heated and cooled protective film-forming film. When the hardness of the heated and cooled protective film-forming film is compared to the hardness of the unheated protective film-forming film at the same temperature, if the heated and cooled protective film-forming film is harder, then this protective film-forming film is thermosetting.

[0020] The protective film-forming film of this embodiment may consist of one layer (single layer) or of two or more layers. When the protective film-forming film consists of multiple layers, these layers may be identical or different from each other, and the combination of these layers is not particularly limited.

[0021] In this specification, not only in the case of protective film-forming films, "multiple layers may be identical or different from one another" means "all layers may be identical, all layers may be different, or only some layers may be identical," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thickness of each layer is different from the other."

[0022] <<Fever-starting temperature>> The exothermic onset temperature of the test specimen in DSC is 160°C or higher, preferably 170°C or higher, and may be, for example, 173°C or higher, 176°C or higher, or 180°C or higher. The higher the exothermic onset temperature, the greater the storage stability of the protective film at room temperature. The upper limit of the heat generation initiation temperature is not particularly limited. For example, in order to easily obtain a protective film, the heat generation initiation temperature may be 195°C or lower. In one embodiment, the exothermic onset temperature may be, for example, 160-195°C, 170-195°C, 173-195°C, 176-195°C, and 180-195°C. However, these are just examples of the exothermic onset temperature.

[0023] The form of the test specimen to be subjected to DSC is not particularly limited, as long as it allows for high-precision DSC. For example, the test specimen can be prepared by laminating multiple protective film-forming films and cutting them into an appropriate shape. A test specimen with a mass of, for example, 4 to 10 mg is sufficient.

[0024] The exothermic start temperature of the specimen in DSC is defined, for example, as the temperature indicated by the intersection of the tangent line at the point where the differential curve of the DSC curve (the curve obtained by plotting the DSC data) first shows a negative value, and the tangent line at the temperature where the differential curve shows a local maximum (the first observed extreme value).

[0025] The temperature at which the test specimen begins to exothermic in DSC can be adjusted by adjusting the type and amount of components contained in the protective film-forming film. For example, if the protective film-forming film contains a curing accelerator (C) described later, the exothermic onset temperature can be more easily adjusted by adjusting the reactivity of the curing accelerator (C). More specifically, the exothermic onset temperature can be increased by, for example, selecting a curing accelerator (C) with a lower reaction onset temperature, or by increasing the content of such a curing accelerator (C). For example, if the protective film-forming film contains a thermosetting agent (B2) described later, it is preferable to select a thermosetting agent (B2) that is solid at room temperature in order to raise the exothermic start temperature.

[0026] The thickness of the protective film is not particularly limited. The thickness of the protective film is preferably 50 μm or less, and may be, for example, 40 μm or less, or 30 μm or less. By keeping the thickness of the protective film below the upper limit, it is possible to avoid the protective film being excessively thick. On the other hand, the thickness of the protective film is preferably 5 μm or more, in order to form a protective film with higher protective performance. In one embodiment, the thickness of the protective film-forming film may be, for example, 5 to 50 μm, 5 to 40 μm, or 5 to 30 μm. However, these are just examples of the thickness of the protective film-forming film.

[0027] In this specification, "thickness of protective film" means the total thickness of the protective film. For example, the thickness of a protective film consisting of multiple layers means the total thickness of all layers constituting the protective film.

[0028] In this specification, "thickness," unless otherwise specified, refers to the average of the thicknesses measured at five randomly selected locations on the object, and can be obtained using a constant-pressure thickness measuring instrument in accordance with JIS K7130.

[0029] The curing conditions when the protective film-forming film is attached to the desired location on the semiconductor wafer and heat-cured to form a protective film are not particularly limited, as long as the degree of curing is sufficient for the protective film to fully perform its function, and can be appropriately selected depending on the type of protective film-forming film.

[0030] For example, the heating temperature during the thermosetting of the protective film may be any of the following: 100-200°C, 110-180°C, or 120-160°C. The heating time during the heat curing process can be set appropriately, taking into account the heating temperature. For example, it may be 3 minutes to 5 hours, 10 minutes to 4 hours, or 30 minutes to 3 hours.

[0031] The protective film-forming film of this embodiment can be attached to the back surface of a semiconductor wafer opposite to the circuit surface, and can be used to form a protective film on the back surface of a semiconductor chip obtained by dividing the semiconductor wafer. The protective film-forming film of this embodiment has good adhesion to the back surface of the semiconductor wafer and provides high protection performance for semiconductor chips. The protective film-forming film of this embodiment suppresses unintended reactions of the components necessary for thermosetting, even when stored at room temperature. In other words, the protective film-forming film of this embodiment has high stability when stored at room temperature. Therefore, for example, even if the protective film-forming film is attached to the back surface of a semiconductor wafer after being stored at room temperature for 30 days, it exhibits good adhesion and high protection performance for semiconductor chips.

[0032] <<Composition for forming protective film>> The protective film-forming film can be formed using a protective film-forming composition (more specifically, a thermosetting protective film-forming composition) containing its constituent materials. For example, a protective film-forming film can be formed by coating the surface to be formed with the protective film-forming composition and drying it as needed. The ratio of components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the ratio of those components in the protective film-forming film.

[0033] The protective film forming the aforementioned protective film may have energy ray curability in addition to thermosetting properties.

[0034] In this specification, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum, and examples include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated, for example, by using high-pressure mercury lamps, fusion lamps, xenon lamps, black lights, or LED lamps as ultraviolet light sources. Electron beams can be irradiated using those generated by electron accelerators, etc. In this specification, "energy ray curable" means the property of hardening when irradiated with energy rays, and "non-energy ray curable" means the property of not hardening even when irradiated with energy rays.

[0035] In a protective film, the ratio of the total content of one or more of the following components in the protective film to the total mass of the protective film is not more than 100% by mass. Similarly, in a protective film-forming composition, the ratio of the total content of one or more of the following components of the protective film-forming composition to the total mass of the protective film-forming composition shall not exceed 100% by mass.

[0036] The coating of the protective film-forming composition can be carried out by known methods, such as using various coaters including air knife coaters, blade coaters, bar coaters, gravure coaters, roll coaters, roll knife coaters, curtain coaters, die coaters, knife coaters, screen coaters, Meyer bar coaters, and kiss coaters.

[0037] The drying conditions for the protective film-forming composition are not particularly limited. However, if the protective film-forming composition contains a solvent as described later, it is preferable to heat-dry it. When a protective film-forming composition containing a solvent is heat-dried, it is preferable to heat-dry it at, for example, 70 to 130°C for 10 seconds to 5 minutes. However, since the protective film-forming composition is thermosetting, it is preferable to heat-dry it in a way that prevents the composition itself and the thermosetting protective film-forming film formed from it from becoming thermosetting.

[0038] A preferred protective film-forming film is one containing a curing accelerator (C), and a more preferred protective film-forming film is one containing a polymer component (A), a thermosetting component (B), a curing accelerator (C), and a filler (D). The polymer component (A) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. In this specification, polymerization reactions also include polycondensation reactions. The composition of the protective film-forming composition will be described in detail below.

[0039] <Protective film forming composition (III)> Examples of preferred protective film-forming compositions include protective film-forming composition (III) containing a curing accelerator (C) (which may be simply abbreviated as "composition (III)" in this specification). It is more preferable that protective film-forming composition (III) contains a polymer component (A), a thermosetting component (B), a curing accelerator (C), and a filler (D).

[0040] [Polymer component (A)] Polymer component (A) is a polymer compound that imparts film-forming properties, flexibility, and other characteristics to the protective film-forming film. In this specification, the polymer compound also includes products of polycondensation reactions.

[0041] The polymer component (A) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0042] Examples of polymer component (A) include acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc., with acrylic resin being preferred.

[0043] Examples of the acrylic resin in polymer component (A) include known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 1,000,000 to 1,500,000, even more preferably 200,000 to 1,200,000, and particularly preferably 300,000 to 1,000,000. A weight-average molecular weight of the acrylic resin above the lower limit improves the film-forming properties of the protective film. A weight-average molecular weight of the acrylic resin below the upper limit makes it easier for the protective film to conform to the uneven surface of the adherend.

[0044] In this specification, "weight-average molecular weight" refers to the polystyrene equivalent value measured by gel permeation chromatography (GPC) unless otherwise specified.

[0045] The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, more preferably -50 to 50°C, and even more preferably -50 to 20°C. When the Tg of the acrylic resin is above the lower limit, for example, the adhesion between the cured protective film and the support sheet is suppressed, and the peelability of the support sheet is moderately improved. When the Tg of the acrylic resin is below the upper limit, the adhesion strength between the thermosetting protective film and its cured product and the adherend is improved.

[0046] If an acrylic resin has m constituent units (where m is an integer greater than or equal to 2), and each of the m monomers that derive these constituent units is sequentially assigned a unique number from 1 to m and named "monomer m", then the glass transition temperature (Tg) of the acrylic resin can be calculated using Fox's formula shown below.

[0047]

number

[0048] [Number] (In the formula, m and W k are the same as described above.)

[0049] As the Tg k , the values described in Polymer Data Handbook, Adhesion Handbook, Polymer Handbook, etc. can be used. For example, the Tg k of the homopolymer of methyl acrylate is 10 °C, and the Tg k of the homopolymer of methyl methacrylate is 105 °C, the Tg k of the homopolymer of 2-hydroxyethyl acrylate is -15 °C, the Tg k of the homopolymer of glycidyl methacrylate is 41 °C, the Tg k of the homopolymer of 2-ethylhexyl acrylate is -70 °C, the Tg k of the homopolymer of acrylic acid is 103 °C, the Tg k of the homopolymer of acrylonitrile is 97 °C, the Tg k of the homopolymer of n-butyl acrylate is -54 °C, and the Tg k of the homopolymer of ethyl acrylate is -24 °C.

[0050] Examples of the acrylic resin include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from the above (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, etc.

[0051] Examples of the (meth)acrylic acid esters constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and (meth Alkyl methacrylates such as isononyl acrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate (lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate (myristyl methacrylate), pentadecyl methacrylate, hexadecyl methacrylate (palmityl methacrylate), heptadecyl methacrylate, octadecyl methacrylate (stearyl methacrylate), etc., in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms; Cycloalkyl esters of (meth)acrylate such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylate aralkyl esters such as benzyl (meth)acrylate; (meth)acrylate dicyclopentenyl ester and other cycloalkenyl (meth)acrylates; (meth)acrylate cycloalkenyloxyalkyl esters such as (meth)acrylate dicyclopentenyloxyethyl ester; (meth)acrylimide; Glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; Hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and other hydroxyl group-containing (meth)acrylate esters; Examples include (meth)acrylic acid esters containing substituted amino groups, such as N-methylaminoethyl (meth)acrylate. Here, "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom.

[0052] In this specification, "(meth)acrylic acid" is a concept that encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid; for example, "(meth)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group," and "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate."

[0053] The monomers that make up the acrylic resin may be just one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0054] The acrylic resin may have functional groups that can bond with other compounds, such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups. The functional groups of the acrylic resin may be bonded to other compounds via a crosslinking agent (F) described later, or they may be directly bonded to other compounds without the crosslinking agent (F).

[0055] In the present invention, a thermoplastic resin other than acrylic resin (hereinafter sometimes simply referred to as "thermoplastic resin") may be used as the polymer component (A) alone without using acrylic resin, or in combination with acrylic resin. Using the thermoplastic resin may improve the peelability of the protective film from the support sheet, or make it easier for the protective film-forming film to conform to the uneven surface of the adherend.

[0056] The weight-average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, and more preferably 3,000 to 80,000.

[0057] The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, and more preferably -20 to 120°C.

[0058] Examples of the thermoplastic resins include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0059] The thermoplastic resin contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0060] In composition (III), the ratio of the polymer component (A) to the total content of all components other than the solvent is preferably 10 to 85% by mass, more preferably 10 to 65% by mass, and even more preferably 10 to 45% by mass, regardless of the type of polymer component (A), and may be, for example, 10 to 35% by mass. This statement is equivalent to saying that, in a protective film-forming film, the ratio of the polymer component (A) content to the total mass of the protective film-forming film is preferably 10 to 85% by mass, more preferably 10 to 65% by mass, even more preferably 10 to 45% by mass, and may be, for example, 10 to 35% by mass, regardless of the type of polymer component (A). This is based on the fact that, in the process of removing the solvent from a solvent-containing resin composition to form a resin film, the amount of components other than the solvent usually does not change, and the ratio of the contents of non-solvent components is the same in the resin composition and the resin film. Therefore, in this specification, hereafter, not limited to the case of protective film-forming films, the content of non-solvent components will only be described in the resin film obtained by removing the solvent from the resin composition.

[0061] Polymer component (A) may also correspond to thermosetting component (B). In the present invention, if composition (III) contains components that correspond to both polymer component (A) and thermosetting component (B), composition (III) is deemed to contain polymer component (A) and thermosetting component (B).

[0062] [Thermosetting component (B)] Thermosetting component (B) is a component for curing the protective film. The thermosetting component (B) contained in composition (III) and the protective film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0063] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy-based thermosetting resins being preferred. In this specification, thermosetting polyimide resin is a general term encompassing a polyimide precursor and a thermosetting polyimide, both of which form a polyimide resin through thermosetting.

[0064] (Epoxy thermosetting resin) Epoxy thermosetting resins consist of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy thermosetting resin contained in composition (III) and the protective film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0065] • Epoxy resin (B1) Examples of epoxy resins (B1) include well-known ones, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenylene skeleton type epoxy resins, and other bifunctional or more epoxy compounds.

[0066] As the epoxy resin (B1), an epoxy resin having unsaturated hydrocarbon groups may be used.

[0067] The number-average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoint of the curability of the protective film-forming film, as well as the strength and heat resistance of the protective film, it is preferably 300 to 30000, more preferably 300 to 10000, and particularly preferably 300 to 3000. The epoxy equivalent of epoxy resin (B1) is preferably 100 to 1000 g / eq, and more preferably 150 to 950 g / eq.

[0068] Epoxy resin (B1) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio of these types can be arbitrarily selected.

[0069] • Thermosetting agent (B2) The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1). Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted to an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted to an anhydride, and more preferably a phenolic hydroxyl group or an amino group.

[0070] Examples of thermosetting agents (B2) that include phenolic curing agents having phenolic hydroxyl groups include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Examples of amine-based curing agents containing an amino group among the thermosetting agents (B2) include dicyandiamide.

[0071] The thermosetting agent (B2) may have an unsaturated hydrocarbon group.

[0072] When a phenolic curing agent is used as the thermosetting agent (B2), it is preferable that the thermosetting agent (B2) has a high softening point or glass transition temperature, as this improves the peelability of the protective film from the support sheet.

[0073] Among the thermosetting agents (B2), the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. The molecular weight of the non-resin component of the thermosetting agent (B2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0074] The thermosetting agent (B2) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio of these types can be arbitrarily selected.

[0075] In terms of achieving a higher exothermic onset temperature of the test specimen in DSC, the thermosetting agent (B2) is preferably solid at room temperature, and examples of such agents include dicyandiamide. In other words, it is preferable that the protective film-forming film contains a thermosetting agent (B2) that is solid at room temperature.

[0076] In composition (III) and the protective film-forming film, the content of the thermosetting agent (B2) is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, per 100 parts by mass of epoxy resin (B1), and may be, for example, 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, or 0.5 to 5 parts by mass. When the content of the thermosetting agent (B2) is above the lower limit, the curing of the protective film-forming film proceeds more easily. When the content of the thermosetting agent (B2) is below the upper limit, the moisture absorption rate of the protective film-forming film is reduced, and the reliability of the package obtained using the protective film-forming film is further improved.

[0077] In composition (III) and the protective film, the ratio of the content of thermosetting agent (B2) that is solid at room temperature to the total content of thermosetting agent (B2) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. For example, it may be 95% by mass or more, 97% by mass or more, and 99% by mass or more, and may be 100% by mass. In other words, composition (III) and the protective film may contain only thermosetting agent (B2) that is solid at room temperature. The higher the ratio, the higher the onset temperature of heat generation of the test specimen in DSC tends to be.

[0078] In composition (III) and the protective film-forming film, the content of thermosetting component (B) is preferably 10 to 70 parts by mass, more preferably 20 to 65 parts by mass, and even more preferably 30 to 60 parts by mass, based on 100 parts by mass of the total content of polymer component (A) and thermosetting component (B). For example, it may be 40 to 55 parts by mass. When the content of thermosetting component (B) is within this range, for example, the adhesion between the cured product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is improved.

[0079] [Curing accelerator (C)] The curing accelerator (C) is an ingredient used to adjust the curing rate of composition (III). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0080] The curing accelerator (C) contained in composition (III) and the protective film-forming film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0081] In terms of achieving a higher exothermic start temperature for the test specimen in DSC, it is preferable that the curing accelerator (C) has a relatively low reaction start temperature. Examples of such accelerators include imidazoles. The protective film forming the aforementioned protective film preferably contains at least imidazoles as a curing accelerator (C).

[0082] When a curing accelerator (C) is used, the content of the curing accelerator (C) in composition (III) and the protective film-forming film is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 7 parts by mass, per 100 parts by mass of the thermosetting component (B), and may be, for example, 0.5 to 5 parts by mass and 0.5 to 3.5 parts by mass. When the content of the curing accelerator (C) is above the lower limit, the effect of using the curing accelerator (C) is more pronounced. When the content of the curing accelerator (C) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerator (C) towards the adhesive interface with the adherend in the protective film-forming film under high temperature and high humidity conditions is enhanced. As a result, the reliability of the semiconductor chip with a protective film obtained using the protective film-forming film is further improved.

[0083] In composition (III) and the protective film-forming film, the ratio of the content of the curing accelerator (C), which is an imidazole, to the total content of the curing accelerator (C) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. For example, it may be 95% by mass or more, 97% by mass or more, and 99% by mass or more, and may be 100% by mass, that is, composition (III) and the protective film-forming film may contain only imidazoles as the curing accelerator (C). The higher the ratio, the higher the exothermic start temperature of the test specimen in DSC tends to be.

[0084] [Filling material (D)] By including a filler (D) in the protective film-forming film, the thermal expansion coefficient of the thermosetting protective film-forming film and the protective film can be easily adjusted. Optimizing this thermal expansion coefficient for the object on which the protective film is formed further improves the reliability of the semiconductor chip with a protective film obtained using the protective film-forming film. Furthermore, including a filler (D) in the thermosetting protective film-forming film can also reduce the moisture absorption rate of the protective film and improve its heat dissipation.

[0085] The filler (D) may be either an organic filler or an inorganic filler, but an inorganic filler is preferred. Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0086] In a protective film-forming composition, in terms of improving the dispersibility of the filler (D) with respect to other components, the silica is preferably silica surface-modified with organic groups, more preferably silica surface-modified with vinyl groups, epoxy groups, phenyl groups, or methacrylic groups, and particularly preferably silica surface-modified with vinyl groups or epoxy groups.

[0087] In a protective film-forming composition, the average particle size of the filler (D) is preferably 0.02 to 2 μm, more preferably 0.05 to 1 μm, and particularly preferably 0.07 to 0.7 μm, in terms of improving the dispersibility of the filler (D) among other components.

[0088] In this specification, "average particle diameter" means the arithmetic mean ([sum of particle diameters of 100 particles in plan view] / 100) obtained by observing the particles in question using an electron microscope, randomly selecting 100 particles, and calculating their particle diameters in plan view. In this case, the maximum value of the line segment obtained by connecting any two points on the outer circumference of the particle in plan view may be used as the particle diameter. For example, with respect to particles in a resin film, such as the filler (D) in a protective film, the average particle size can be determined by the method described above after the resin component has been removed by firing the resin film.

[0089] The composition (III) and the filler (D) contained in the protective film-forming film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0090] If the protective film-forming film contains a filler (D), the ratio of the filler (D) content to the total mass of the protective film-forming film may be 40% by mass or more, but is preferably 50% by mass or more, for example, it may be 55% by mass or more and 60% by mass or more. By having a ratio equal to or greater than the lower limit, the protective film-forming film can form a protective film with higher protective performance, for example, the chipping suppression effect on semiconductor chips with protective films is enhanced.

[0091] When the protective film-forming film contains a filler (D), the ratio of the filler (D) content to the total mass of the protective film-forming film may be 65% by mass or less, but is preferably 63% by mass or less, for example, it may be 57% by mass or less and 50% by mass or less. When the ratio is below the upper limit, the effect of suppressing warping of the laminate between the protective film and the adherend is enhanced when the protective film-forming film is attached to the adherend to be protected, for example, the effect of suppressing warping in semiconductor wafers with a protective film is enhanced.

[0092] In the protective film-forming film, the ratio of the filler (D) content to the total mass of the protective film-forming film can be appropriately adjusted within a range set by arbitrarily combining any of the lower and upper limits mentioned above. In one embodiment, the aforementioned proportion may be any of 40-65% by mass, 40-63% by mass, 40-57% by mass or less, or 40-50% by mass or less; or any of 50-65% by mass, 50-63% by mass, or 50-57% by mass; or any of 55-65% by mass, or 55-63% by mass; or 60-65% by mass. However, these are merely examples of the aforementioned proportions.

[0093] [Coupling agent (E)] Composition (III) and the protective film-forming film may contain a coupling agent (E). By using a coupling agent (E) that has a functional group that can react with an inorganic compound or an organic compound, the adhesion of the protective film formed from the protective film-forming film to the adherend can be improved. Furthermore, by using a coupling agent (E), the water resistance of the protective film is improved without impairing its heat resistance.

[0094] The coupling agent (E) is preferably a compound having a functional group that can react with the functional groups of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

[0095] Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples include aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfan, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane.

[0096] The coupling agent (E) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0097] When a coupling agent (E) is used, the content of the coupling agent (E) in composition (III) and protective film is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the total content of polymer component (A) and thermosetting component (B). By having the content of the coupling agent (E) within this range, the chemical compatibility between the protective film-forming film and the adherend can be slightly controlled, making it easier to adjust the tackiness and peelability. On the other hand, when the content of the coupling agent (E) is above the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the protective film-forming film to the adherend, can be obtained more significantly. When the content of the coupling agent (E) is below the upper limit, outgassing is further suppressed.

[0098] [Crosslinking agent (F)] When polymer component (A) is a polymer having functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds, such as the acrylic resin mentioned above, composition (III) and the protective film-forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for crosslinking the functional groups in polymer component (A) with other compounds, and by crosslinking in this way, the adhesive strength and cohesive strength of the protective film-forming film can be adjusted.

[0099] Examples of crosslinking agents (F) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0100] The crosslinking agent (F) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0101] In terms of improving the long-term stability of the protective film-forming composition, it is preferable that composition (III) does not contain a crosslinking agent (F), or that the content of the crosslinking agent (F) in composition (III) is low, for example, less than 0.01 parts by mass per 100 parts by mass of polymer component (A). In contrast, when using a certain amount or more of the crosslinking agent (F), the content of the crosslinking agent (F) in composition (III) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, based on the content of polymer component (A) per 100 parts by mass. When the content of the crosslinking agent (F) is above the lower limit, the effect of using the crosslinking agent (F) is obtained more significantly. When the content of the crosslinking agent (F) is below the upper limit, the overuse of the crosslinking agent (F) is suppressed.

[0102] [Energy ray curable resin (G)] Composition (III) and the protective film may contain an energy-curable resin (G). The protective film contains an energy-curable resin (G), which allows its properties to be altered by irradiation with energy rays.

[0103] The energy-ray curable resin (G) is an energy-ray curable compound, or an oligomer or polymer (polymer) that can be considered to be synthesized from an energy-ray curable compound. Examples of the energy ray curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0104] Examples of the aforementioned acrylate compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and other chains. Examples include cyclic aliphatic skeleton-containing (meth)acrylates; cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

[0105] The weight-average molecular weight of the energy-ray curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0106] The energy-curable compound used in the synthesis of the oligomer or polymer may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0107] The energy-curable resin (G) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0108] When using an energy-ray curable resin (G), the ratio of the content of the energy-ray curable resin (G) to the total mass of composition (III) is preferably 1 to 30% by mass, more preferably 5 to 25% by mass, and particularly preferably 10 to 20% by mass.

[0109] [Photopolymerization initiator (H)] If composition (III) and the protective film-forming film contain an energy-ray curable resin (G), they may also contain a photopolymerization initiator (H) to efficiently advance the polymerization reaction of the energy-ray curable resin (G).

[0110] Examples of photopolymerization initiators (H) in composition (III) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, and 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone; and bis(2,4,6-trimethylbenzoyl)phenyl Examples include acylphosphine oxide compounds such as phosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone. Furthermore, examples of photopolymerization initiators (H) include photosensitizers such as amines.

[0111] The photopolymerization initiator (H) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0112] When a photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in composition (III) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass, based on the content of 100 parts by mass of the energy ray curable resin (G).

[0113] [Coloring agent (I)] The composition (III) and the protective film preferably contain a colorant (I). By including a colorant (I), the light transmittance of the protective film and the protective film can be easily adjusted.

[0114] Examples of colorants (I) include known ones such as inorganic pigments, organic pigments, and organic dyes.

[0115] Examples of the aforementioned organic pigments and organic dyes include aminium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squalium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyririum-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex salt dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triallylmethane-based dyes, anthraquinone-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and surene-based dyes.

[0116] Examples of the inorganic pigments mentioned above include carbon black, cobalt-based dyes, iron-based dyes, chromium-based dyes, titanium-based dyes, vanadium-based dyes, zirconium-based dyes, molybdenum-based dyes, ruthenium-based dyes, platinum-based dyes, ITO (indium tin oxide)-based dyes, ATO (antimony tin oxide)-based dyes, and the like.

[0117] The colorants (I) contained in composition (III) and the protective film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0118] When using a coloring agent (I), the content of the coloring agent (I) in the protective film-forming film can be appropriately adjusted according to the purpose. For example, by adjusting the content of the coloring agent (I) in the protective film-forming film and thereby adjusting the light transmittance of the protective film-forming film, the visibility of the printed markings when laser printing is performed on the protective film-forming film or protective film can be adjusted. Furthermore, by adjusting the content of the coloring agent (I) in the protective film-forming film, it is possible to improve the aesthetic appearance of the protective film or make grinding marks on the back surface of the wafer less visible. Considering these points, the ratio of the content of the coloring agent (I) to the total mass of the protective film-forming film is preferably 0.1 to 10% by mass, more preferably 0.1 to 7.5% by mass, and particularly preferably 0.1 to 5% by mass. When the ratio is above the lower limit, the effect of using the coloring agent (I) is more pronounced. For example, when the protective film-forming film is peeled off from the adherend, it is easy to visually confirm whether or not any residue of the protective film-forming film remains on the adherend. By keeping the aforementioned ratio below the aforementioned upper limit, excessive use of coloring agent (I) is suppressed.

[0119] [General-purpose additive (J)] Composition (III) and the protective film-forming film may contain a general-purpose additive (J) within a range that does not impair the effects of the present invention. The general-purpose additive (J) may be any known additive and can be arbitrarily selected according to the purpose, and is not particularly limited, but preferred examples include plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0120] The general-purpose additive (J) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. The content of composition (III) and the general-purpose additive (J) in the protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[0121] [solvent] Composition (III) preferably further contains a solvent. Composition (III) containing a solvent has good handling properties. In this specification, unless otherwise specified, the term "solvent" includes not only substances that dissolve the target component but also dispersion media that disperse the target component.

[0122] The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The solvent contained in composition (III) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0123] More preferred solvents for composition (III) include, for example, methyl ethyl ketone, toluene, and ethyl acetate, as they allow for more uniform mixing of the components in composition (III).

[0124] The solvent content of composition (III) is not particularly limited and may be appropriately selected depending on the type of components other than the solvent.

[0125] <Method for producing protective film-forming composition (III)> Composition (III) is obtained by blending the components that constitute it. There are no particular restrictions on the order in which each component is added during formulation, and two or more components may be added simultaneously. The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0126] ◎Examples of protective film-forming films Figure 1 is a schematic cross-sectional view showing an example of a protective film-forming film according to this embodiment. Note that, for convenience in order to make the features of the present invention easier to understand, the figures used in the following description may show enlarged versions of key parts, and the dimensional ratios of each component may not be the same as in reality.

[0127] The protective film-forming film 13 shown herein has a first release film 151 on one side (sometimes referred to as the "first side" in this specification) 13a and a second release film 152 on the other side (sometimes referred to as the "second side" in this specification) 13b opposite to the first side 13a. Such protective film-forming film 13 is suitable for storage, for example, in a roll form.

[0128] The exothermic start temperature of the test specimen made from the protective film-forming film 13 in the above-mentioned DSC is 160°C or higher.

[0129] The protective film-forming film 13 can be formed using the protective film-forming composition described above.

[0130] The first release film 151 and the second release film 152 may both be known types. The first release film 151 and the second release film 152 may be the same as each other, or they may be different from each other, for example, in that they require different peeling forces when peeled from the protective film forming film 13.

[0131] In Figure 1, the protective film-forming film 13 is formed when either the first release film 151 or the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to the back surface of the semiconductor wafer (not shown). When a support sheet or dicing sheet, described later, is used, the remaining part of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface of the protective film-forming film 13 becomes the surface to be attached to the support sheet or dicing sheet.

[0132] Figure 1 shows an example in which the release film is provided on both sides (first surface 13a and second surface 13b) of the protective film forming film 13. However, the release film may be provided on only one side of the protective film forming film 13, that is, only the first surface 13a or only the second surface 13b.

[0133] The protective film-forming film of this embodiment, when used in combination with a support sheet described later, can form a composite sheet for forming a protective film that can perform both protective film formation and dicing simultaneously. Such a composite sheet for forming a protective film will be described below.

[0134] ◇ Composite sheet for forming protective film A composite sheet for forming a protective film according to one embodiment of the present invention comprises a support sheet and a protective film forming film provided on one surface of the support sheet, wherein the protective film forming film is the protective film forming film according to the above-described embodiment of the present invention. The protective film-forming composite sheet of this embodiment can be attached to the back surface of a semiconductor wafer by the protective film-forming film contained therein.

[0135] In this specification, as long as the laminated structure of the support sheet and the cured protective film is maintained even after the protective film has hardened, this laminated structure will be referred to as a "composite sheet for forming a protective film."

[0136] The following describes in detail each layer that constitutes the composite sheet for forming the protective film.

[0137] ◎Support sheet The support sheet may consist of one layer (single layer) or of two or more layers. If the support sheet consists of multiple layers, the constituent materials and thicknesses of these layers may be the same or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention.

[0138] The support sheet may be transparent or opaque, and may be colored depending on the purpose. If the protective film is energy ray curable, the support sheet is preferably one that transmits energy rays.

[0139] Examples of support sheets include those comprising a base material and an adhesive layer provided on one surface of the base material; or those consisting only of the base material. When the support sheet includes an adhesive layer, the adhesive layer is positioned between the base material and the protective film in the case of a composite sheet for forming a protective film.

[0140] When a support sheet comprising a base material and an adhesive layer is used, the adhesion and peelability between the support sheet and the protective film-forming film can be easily adjusted in the composite sheet for forming the protective film. When a support sheet consisting only of the base material is used, a composite sheet for forming a protective film can be manufactured at a low cost.

[0141] Examples of the composite sheet for forming the protective film in this embodiment will be described below with reference to the drawings, according to each type of support sheet.

[0142] ◎ An example of a composite sheet for forming a protective film. Figure 2 is a schematic cross-sectional view showing an example of a composite sheet for forming a protective film according to this embodiment. In Figures 2 and beyond, components identical to those shown in previously explained figures are denoted by the same reference numerals, and their detailed explanations are omitted.

[0143] The protective film-forming composite sheet 101 shown herein comprises a support sheet 10 and a protective film-forming film 13 provided on one surface (sometimes referred to as the "first surface" in this specification) 10a of the support sheet 10. The support sheet 10 comprises a base material 11 and an adhesive layer 12 provided on one surface (first surface) 11a of the base material 11. In the protective film-forming composite sheet 101, the adhesive layer 12 is positioned between the base material 11 and the protective film-forming film 13. In other words, the protective film-forming composite sheet 101 is constructed by laminating a base material 11, an adhesive layer 12, and a protective film-forming film 13 in this order in the thickness direction. The first surface 10a of the support sheet 10 is the same as the surface 12a of the adhesive layer 12 that is opposite to the substrate 11 side (which may be referred to as the "first surface" in this specification).

[0144] The protective film-forming composite sheet 101 further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13. In the protective film-forming composite sheet 101, a protective film-forming film 13 is laminated over the entire or nearly entire surface of the first surface 12a of the adhesive layer 12, and a jig adhesive layer 16 is laminated on a portion of the surface 13a of the protective film-forming film 13 opposite to the adhesive layer 12 (sometimes referred to as the "first surface" in this specification), i.e., in the area near the periphery. Furthermore, a release film 15 is laminated on the area of ​​the first surface 13a of the protective film-forming film 13 where the jig adhesive layer 16 is not laminated, and on the surface 16a of the jig adhesive layer 16 opposite to the protective film-forming film 13 (sometimes referred to as the "first surface" in this specification). A support sheet 10 is provided on the surface 13b of the protective film-forming film 13 opposite to the first surface 13a (sometimes referred to as the "second surface" in this specification).

[0145] In the case of the protective film-forming composite sheet 101, as well as in other cases of the protective film-forming composite sheet of this embodiment, the release film (for example, the release film 15 shown in Figure 2) can be of any configuration, and the protective film-forming composite sheet of this embodiment may or may not include a release film.

[0146] The adhesive layer 16 for the jig is used to fix the composite sheet 101 for forming a protective film to a jig such as a ring frame. The jig adhesive layer 16 may, for example, have a single-layer structure containing an adhesive component or a tack component, or it may have a multi-layer structure comprising a core sheet and layers containing an adhesive component or a tack component provided on both sides of the sheet.

[0147] The protective film-forming composite sheet 101 is used after the release film 15 has been removed, with the back surface of a semiconductor wafer attached to the first surface 13a of the protective film-forming film 13, and further, the first surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame.

[0148] Figure 3 is a schematic cross-sectional view showing another example of the composite sheet for forming a protective film according to this embodiment. The protective film-forming composite sheet 102 shown here is the same as the protective film-forming composite sheet 101 shown in Figure 2, except that the size of the protective film-forming film is different and it does not have a jig adhesive layer 16.

[0149] More specifically, in the protective film-forming composite sheet 102, the protective film-forming film 23 is laminated on a portion of the first surface 12a of the adhesive layer 12, that is, on the central region in the width direction (left-right direction in Figure 3) of the adhesive layer 12. The release film 15 is laminated on the side of the protective film-forming film 23 opposite to the adhesive layer 12 (sometimes referred to as the "first surface" in this specification) 23a, and on the area of ​​the first surface 12a of the adhesive layer 12 where the protective film-forming film 23 is not laminated. A support sheet 10 is provided on the side of the protective film-forming film 23 opposite to the first surface 23a (sometimes referred to as the "second surface" in this specification) 23b.

[0150] The composite sheet for forming the protective film in this embodiment is not limited to those shown in Figures 2 and 3. Within the limits that do not impair the effects of the present invention, some components of those shown in Figures 2 and 3 may be modified or deleted, or other components may be added to those described herein.

[0151] Next, we will describe each layer that makes up the support sheet in more detail.

[0152] ○Base material The substrate is in the form of a sheet or film, and its constituent materials include, for example, various resins. Examples of the aforementioned resins include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (polymers obtained using ethylene as a monomer); and vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer (using vinyl chloride as a monomer). Examples of the obtained resins include: polystyrene; polycycloolefins; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and all aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; polyether ketones, etc. Furthermore, the resin may also include, for example, a polymer alloy such as a mixture of the polyester and other resins. In the polymer alloy of polyester and other resins, it is preferable that the amount of the resin other than polyester is relatively small. Furthermore, examples of the resin include crosslinked resins obtained by crosslinking one or more of the resins exemplified so far, and modified resins such as ionomers using one or more of the resins exemplified so far. The aforementioned resin is preferably polypropylene or polybutylene terephthalate, as it offers excellent heat resistance.

[0153] The resin constituting the base material may consist of only one type, or two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0154] The base material may consist of one layer (single layer) or of two or more layers. If it consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0155] The thickness of the substrate is preferably 50 to 300 μm, and more preferably 60 to 100 μm. Having the substrate thickness within this range improves the flexibility of the composite sheet for protective film formation and its suitability for adhesion to the wafer. Here, "substrate thickness" refers to the total thickness of the substrate. For example, the thickness of a substrate consisting of multiple layers refers to the total thickness of all the layers that make up the substrate.

[0156] In addition to the main constituent materials such as the aforementioned resin, the base material may also contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and plasticizers.

[0157] The substrate may be transparent or opaque, and may be colored or have other layers deposited on it, depending on the purpose. If the protective film forming the film has energy ray curability, the substrate is preferably one that transmits energy rays.

[0158] The substrate may have its surface treated with sandblasting, solvent treatment, or other surface treatments to adjust its adhesion to the layer provided thereon (for example, an adhesive layer, a protective film-forming film, or the aforementioned other layer); oxidation treatments such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or hot air treatment; lipophilic treatment; hydrophilic treatment, etc. The substrate may also have its surface treated with a primer.

[0159] The base material may contain components within a specific range (e.g., resin, etc.) to have adhesive properties on at least one surface.

[0160] The substrate can be manufactured by known methods. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the resin.

[0161] ○ Adhesive layer The adhesive layer is in the form of a sheet or film and contains an adhesive. Examples of the adhesive include adhesive resins such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, polycarbonate, and ester resin.

[0162] The adhesive layer may consist of one layer (single layer) or of two or more layers. If it consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0163] The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 1 to 60 μm, and especially preferably 1 to 30 μm. Here, "thickness of the adhesive layer" refers to the total thickness of the adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers refers to the total thickness of all the layers that make up the adhesive layer.

[0164] The adhesive layer may be transparent or opaque, and may be colored depending on the purpose. If the protective film is energy ray curable, the adhesive layer is preferably one that allows energy rays to pass through.

[0165] The adhesive layer may be either energy-ray curable or non-energy-ray curable. The physical properties of the energy-ray curable adhesive layer can be adjusted before and after curing. For example, by curing the energy-ray curable adhesive layer before picking up the protective film-coated chip (described later), the protective film-coated chip can be picked up more easily.

[0166] In this specification, even after the energy-ray curable adhesive layer has been cured by energy rays, as long as the laminated structure of the substrate and the cured product of the energy-ray curable adhesive layer is maintained, this laminated structure will be referred to as a "support sheet".

[0167] An adhesive layer can be formed using an adhesive composition containing an adhesive. For example, an adhesive layer can be formed on the desired area by applying the adhesive composition to the surface on which the adhesive layer is to be formed and drying it as needed. The ratio of components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of those components in the adhesive layer.

[0168] The adhesive composition can be coated and dried, for example, in the same manner as the coating and drying of the protective film-forming composition described above.

[0169] When the adhesive layer is energy ray curable, examples of energy ray curable adhesive compositions include: adhesive composition (I-1) containing a non-energy ray curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy ray curable compound; adhesive composition (I-2) containing an energy ray curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") in which an unsaturated group is introduced into the side chain of the non-energy ray curable adhesive resin (I-1a); and adhesive composition (I-3) containing the aforementioned adhesive resin (I-2a) and an energy ray curable compound.

[0170] When the adhesive layer is non-energy ray curable, examples of non-energy ray curable adhesive compositions include adhesive compositions (I-4) containing the non-energy ray curable adhesive resin (I-1a).

[0171] [Non-energy ray curable adhesive resin (I-1a)] The adhesive resin (I-1a) is preferably an acrylic resin. Examples of the acrylic resin include acrylic polymers having at least one structural unit derived from an alkyl (meth)acrylate ester.

[0172] The acrylic polymer preferably has, in addition to structural units derived from alkyl (meth)acrylate esters, structural units derived from functional group-containing monomers. Examples of the functional group-containing monomers include those in which the functional group reacts with a crosslinking agent described later to form a starting point for crosslinking. Examples of the functional group-containing monomers include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, and the like.

[0173] The acrylic polymer may have structural units derived from other monomers, in addition to structural units derived from alkyl (meth)acrylate esters and structural units derived from functional group-containing monomers. The other monomers mentioned above are not particularly limited as long as they can be copolymerized with alkyl (meth)acrylate esters, etc. Examples of the other monomers mentioned above include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0174] In the aforementioned adhesive compositions (I-1), (I-2), (I-3), and (I-4) (hereinafter, these adhesive compositions will be collectively referred to as "adhesive compositions (I-1) to (I-4)"), the constituent units of the acrylic resin, such as the acrylic polymer, may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0175] The adhesive resin (I-1a) contained in adhesive composition (I-1) or adhesive composition (I-4) may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0176] In an adhesive layer formed from adhesive composition (I-1) or adhesive composition (I-4), the ratio of the content of adhesive resin (I-1a) to the total mass of the adhesive layer is preferably 5 to 99% by mass.

[0177] [Energy ray curable adhesive resin (I-2a)] The adhesive resin (I-2a) can be obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy-ray polymerizable unsaturated group.

[0178] The aforementioned unsaturated group-containing compound is a compound that, in addition to the energy-ray polymerizable unsaturated group, has a group that can bond to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a). Examples of the energy-ray polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), and the (meth)acryloyl group, which is preferred. Examples of groups that can bond to functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups that can bond to hydroxyl groups or amino groups, and hydroxyl groups and amino groups that can bond to carboxyl groups or epoxy groups.

[0179] Examples of the unsaturated group-containing compounds include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

[0180] The adhesive resin (I-2a) contained in the adhesive composition (I-2) or (I-3) may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0181] In an adhesive layer formed from adhesive composition (I-2) or (I-3), the ratio of the content of adhesive resin (I-2a) to the total mass of the adhesive layer is preferably 5 to 99% by mass.

[0182] [Energy ray curable compound] The energy-ray curable compound contained in the adhesive composition (I-1) or (I-3) includes monomers or oligomers having energy-ray polymerizable unsaturated groups that can be cured by irradiation with energy rays.

[0183] Examples of monomers among energy-ray curable compounds include polyvalent (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; and epoxy (meth)acrylate. Examples of energy-ray curable compounds include oligomers, which are polymers of the monomers exemplified above.

[0184] The energy ray curable compound contained in the adhesive composition (I-1) or (I-3) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0185] In an adhesive layer formed from adhesive composition (I-1) or (I-3), the ratio of the content of the energy ray curable compound to the total mass of the adhesive layer is preferably 1 to 95% by mass.

[0186] [Crosslinking agent] When the acrylic polymer used as the adhesive resin (I-1a) has structural units derived from functional group-containing monomers in addition to structural units derived from alkyl (meth)acrylate, it is preferable that the adhesive composition (I-1) or (I-4) further contains a crosslinking agent. Furthermore, when using the acrylic polymer having functional group-containing monomer-derived structural units, similar to those in the tacky resin (I-1a), as the tacky resin (I-2a), the adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

[0187] The crosslinking agent reacts, for example, with the functional group to crosslink adhesive resins (I-1a) with each other or adhesive resins (I-2a) with each other. Examples of crosslinking agents include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group) such as hexa[1-(2-methyl)-aziridinyl]triphosphotriazine; metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate; and isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

[0188] The crosslinking agent contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0189] In the adhesive composition (I-1) or (I-4), the crosslinking agent content is preferably 0.01 to 50 parts by mass per 100 parts by mass of the adhesive resin (I-1a). In the adhesive composition (I-2) or (I-3), the crosslinking agent content is preferably 0.01 to 50 parts by mass per 100 parts by mass of the adhesive resin (I-2a).

[0190] [Photopolymerization initiator] The adhesive compositions (I-1), (I-2), and (I-3) (hereinafter collectively referred to as "adhesive compositions (I-1) to (I-3)") may further contain a photopolymerization initiator. Adhesive compositions (I-1) to (I-3) containing a photopolymerization initiator will undergo a sufficient curing reaction even when irradiated with relatively low-energy rays such as ultraviolet light.

[0191] Examples of the photopolymerization initiator include those similar to the photopolymerization initiator (H) described above.

[0192] The photopolymerization initiator contained in the adhesive compositions (I-1) to (I-3) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0193] In the adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the energy ray curable compound. In the adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the adhesive resin (I-2a). In the adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray curable compound.

[0194] [Other additives] The adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above-mentioned components, as long as they do not impair the effects of the present invention. Other known additives include, for example, antistatic agents, antioxidants, plasticizers, fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, and crosslinking accelerators (catalysts). A reaction retarder is, for example, a component that suppresses the unintended crosslinking reaction that occurs in adhesive compositions (I-1) to (I-4) during storage due to the action of a catalyst mixed in them. Examples of reaction retarders include those that form a chelate complex by chelation with the catalyst, and more specifically, those that have two or more carbonyl groups (-C(=O)-) in one molecule.

[0195] The other additives contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0196] The content of other additives in adhesive compositions (I-1) to (I-4) is not particularly limited and may be appropriately selected depending on their type.

[0197] [solvent] Adhesive compositions (I-1) to (I-4) may contain a solvent. The presence of a solvent in adhesive compositions (I-1) to (I-4) improves their applicability to the surface to be coated.

[0198] The solvent is preferably an organic solvent, and examples of such organic solvents include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

[0199] The solvent contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0200] The solvent content of adhesive compositions (I-1) to (I-4) is not particularly limited and may be adjusted as appropriate.

[0201] ○ Method for manufacturing adhesive compositions The adhesive composition can be manufactured in the same manner as the protective film-forming composition described earlier, except that the types of components used are different.

[0202] ◇Method for manufacturing a composite sheet for forming a protective film The composite sheet for forming the protective film can be manufactured by laminating the above-mentioned layers in corresponding positional relationships and, if necessary, adjusting the shape of some or all of the layers. The method for forming each layer is as described above.

[0203] For example, when manufacturing a support sheet and laminating an adhesive layer onto a substrate, the above-mentioned adhesive composition can be applied to the substrate and dried as necessary. Alternatively, an adhesive layer can be laminated onto a substrate by applying an adhesive composition to a release film, drying it as needed to form an adhesive layer on the release film, and then bonding the exposed surface of this adhesive layer to one surface of the substrate. In this case, it is preferable to apply the adhesive composition to the release surface of the release film. Furthermore, the release film in this case can be removed at either the manufacturing or usage stage of the protective film-forming composite sheet. Up to this point, we have used the example of laminating an adhesive layer on a substrate, but the method described above can also be applied to cases where other layers besides the adhesive layer are laminated on the substrate.

[0204] On the other hand, for example, when laminating a protective film-forming film on top of an adhesive layer already laminated on a substrate, it is possible to directly form the protective film-forming film by coating the adhesive layer with a protective film-forming composition. Layers other than the protective film-forming film can also be laminated on the adhesive layer in a similar manner using a composition for forming that layer. Thus, when forming a new layer (hereinafter abbreviated as "second layer") on top of any layer already laminated on a substrate (hereinafter abbreviated as "first layer") to form a continuous two-layer laminated structure (in other words, a laminated structure of the first and second layers), a method can be applied in which the composition for forming the second layer is coated onto the first layer and dried as necessary. However, it is preferable to pre-form the second layer on the release film using a composition for forming it, and then bond the exposed surface of the pre-formed second layer opposite to the side in contact with the release film to the exposed surface of the first layer to form a continuous two-layer laminated structure. In this case, it is preferable to coat the release treatment surface of the release film with the composition. The release film may be removed as needed after the laminated structure is formed. Here, we have given an example of laminating a protective film on an adhesive layer, but the target laminated structure can be arbitrarily selected, for example, when laminating a layer (film) other than a protective film on an adhesive layer.

[0205] Thus, since all layers other than the substrate that make up the composite sheet for forming a protective film can be pre-formed on a release film and laminated by bonding them to the surface of the target layer, the composite sheet for forming a protective film can be manufactured by appropriately selecting the layers to which such a process is employed as needed.

[0206] In addition, the composite sheet for forming a protective film is usually stored with a release film attached to the surface of the outermost layer (e.g., the protective film-forming film) opposite to the support sheet. Therefore, a composition for forming the outermost layer, such as a protective film-forming composition, is applied to this release film (preferably its release-treated surface), and dried as necessary to form the outermost layer on the release film. The remaining layers are then laminated on the exposed surface opposite to the side of this layer that is in contact with the release film, and the release film is not removed, resulting in a composite sheet for forming a protective film with a release film.

[0207] ◇Manufacturing method for semiconductor devices (Method of using protective film-forming film and composite sheet for protective film formation) The protective film-forming film and the composite sheet for forming the protective film can be used to manufacture the semiconductor chip with the protective film, and further to manufacture a semiconductor device using the same.

[0208] The semiconductor device manufacturing method of this embodiment includes: an attachment step of attaching one side of the protective film forming film, or the exposed side of the protective film forming film in the protective film forming composite sheet, to the back surface of a semiconductor wafer; a heat curing step after the attachment step of heat curing the protective film forming film to form a protective film; a printing step after the heat curing step of laser printing on the side of the protective film on the support sheet side of the protective film in the protective film forming composite sheet if the protective film forming composite sheet is used, or on the other side of the protective film if the protective film forming film that does not constitute the protective film forming composite sheet is used; and a printing step after the printing step of laser printing on the support sheet in the protective film forming composite sheet if the protective film forming composite sheet is used. The present invention provides a processing step of producing a semiconductor chip with a protective film, comprising the semiconductor chip and the cut protective film provided on the back surface of the semiconductor chip, by dividing the semiconductor wafer into semiconductor chips, cutting the protective film along the division points of the semiconductor wafer, and, if a protective film forming film that does not constitute a composite sheet for forming the protective film is used, attaching a dicing sheet to the other side of the protective film, dividing the semiconductor wafer into semiconductor chips on the dicing sheet, and cutting the protective film along the division points of the semiconductor wafer; and a pickup step of separating the semiconductor chip with a protective film from the dicing sheet or support sheet and picking it up after the processing step.

[0209] The protective film-forming film exhibits high stability when stored at room temperature. Therefore, in the manufacturing method described above, the effects of the present invention are most strongly expressed when the protective film-forming film is used after being stored at room temperature. For example, in the semiconductor device manufacturing method of this embodiment, the protective film-forming composite sheet, or the protective film-forming film that does not constitute the protective film-forming composite sheet, may be used in the bonding step after being stored at room temperature for 30 days.

[0210] The following describes the manufacturing method of semiconductor devices, with reference to diagrams. Figure 4 is a schematic cross-sectional view illustrating an example of a semiconductor device manufacturing method of this embodiment using a composite sheet for forming a protective film (sometimes referred to as "manufacturing method (1)" in this specification). Here, we will describe the case using the composite sheet 101 for forming a protective film shown in Figure 2.

[0211] <<Manufacturing method (1)>> <Pasting process> In the bonding step of the manufacturing method (1) described above, as shown in Figure 4(a), the protective film forming film 13 from the protective film forming composite sheet 101 from which the release film 15 has been removed is bonded to the back surface 9b of the semiconductor wafer 9, thereby producing a semiconductor wafer 901 with a protective film forming film, which comprises the semiconductor wafer 9 and the protective film forming film 13 provided on the back surface 9b of the semiconductor wafer 9. The protective film forming film 13 has its exposed first surface 13a bonded to the back surface 9b of the semiconductor wafer 9. In Figure 4(a), reference numeral 9a indicates the circuit side of the semiconductor wafer 9.

[0212] Note that in Figure 4, the circuit and protruding electrodes on the circuit surface of the semiconductor wafer or semiconductor chip are omitted from the illustration. This is also the case in subsequent figures.

[0213] The protective film 13 can be attached to the semiconductor wafer 9 by known methods, such as using a roll.

[0214] The conditions for attaching the protective film-forming film 13 to the semiconductor wafer 9 are not particularly limited. Typically, the temperature of the protective film-forming film 13 during attachment (attachment temperature) is preferably 20 to 100°C, and more preferably 65 to 85°C. The speed at which the protective film-forming film 13 is attached (attachment speed) is preferably 0.1 to 2 m / min, and the pressure applied to the protective film-forming film 13 during attachment (attachment pressure) is preferably 0.1 to 0.6 MPa.

[0215] Since the exothermic start temperature of the test specimen made from the protective film-forming film 13 in the above-mentioned DSC is 160°C or higher, the adhesive properties of the protective film-forming film 13 to the semiconductor wafer 9 are good during the bonding process. For example, even when using the protective film-forming film 13 after storage at room temperature, the adhesive properties of the protective film-forming film 13 to the semiconductor wafer 9 are good, and as a result, the protective performance of the protective film on the semiconductor chip is also high.

[0216] <Thermosetting process> In the manufacturing method (1), after the bonding step, the thermal curing step involves thermal curing the protective film-forming film 13 in the semiconductor wafer 901 with the protective film-forming film to form a protective film 13' as shown in Figure 4(b). As a result, the semiconductor wafer 901 with the protective film-forming film becomes a semiconductor wafer 901' with a protective film, comprising a semiconductor wafer 9 and a protective film 13' provided on the back surface 9b of the semiconductor wafer 9. In Figure 4(b), reference numeral 13b' indicates the second surface of the protective film 13' and corresponds to the second surface 13b of the protective film-forming film 13. Reference numeral 13a' indicates the first surface of the protective film 13' and corresponds to the first surface 13a of the protective film-forming film 13. In Figure 4(b), the composite sheet for protective film formation after the protective film-forming film 13 has been heat-cured is shown with the new reference numeral 101'.

[0217] In the thermosetting process, the heating temperature and heating time for the thermosetting of the protective film-forming film 13 are as described above.

[0218] As explained above, when a protective film-forming film 13 is used in which the content of filler (D) relative to the total mass of the protective film-forming film is 50% by mass or more, the protective film 13' has high protective performance and a high protective effect on the semiconductor wafer 901' with the protective film.

[0219] As explained above, when a protective film-forming film 13 is used in which the ratio of the filler (D) content to the total mass of the protective film-forming film is 65% by mass or less, the effect of suppressing warping in the semiconductor wafer 901' with the protective film is enhanced.

[0220] <Printing process> In the printing step following the thermosetting step of manufacturing method (1), as shown in Figure 4(c), laser printing is performed on the surface of the protective film 13' in the protective film-forming composite sheet 101' that is on the support sheet 10 side (i.e., the second surface 13b') by irradiating it with laser light R. Laser printing can be performed using known methods. For example, good laser printing can be achieved by irradiating with laser light R at a wavelength of 300 to 1100 nm and a scan speed of 50 to 1000 mm / s. Typical wavelengths of laser light R include, for example, 355 nm, 532 nm, and 1064 nm, but these are just examples.

[0221] <Processing process> In the manufacturing method (1), after the printing step, in the processing step, the semiconductor wafer 9 is divided into semiconductor chips 90 on the support sheet 10 in the protective film forming composite sheet 101', and the protective film 13' is cut along the division points of the semiconductor wafer 9. As a result, as shown in Figure 4(d), a semiconductor chip 913' with a protective film is produced, comprising a semiconductor chip 90 and the protective film 130' provided on the back surface 90b of the semiconductor chip 90 after cutting, and a group of semiconductor chips with a protective film 902 is produced, in which multiple semiconductor chips with protective films 913' are aligned and fixed on the support sheet 10. In Figure 4(c), reference numeral 130a' indicates the first surface of the protective film 130' after cutting, and corresponds to the first surface 13a' of the protective film 13'. Reference numeral 130b' indicates the second surface of the protective film 130' after cutting, and corresponds to the second surface 13b' of the protective film 13'. Reference numeral 90a indicates the circuit surface of the semiconductor chip 90, and corresponds to the circuit surface 9a of the semiconductor wafer 9.

[0222] In the processing steps of manufacturing method (1), for example, the splitting of the semiconductor wafer 9 and the cutting of the protective film 13' may be performed simultaneously, or the splitting of the semiconductor wafer 9 may be performed first, followed by the cutting of the protective film 13'. In manufacturing method (1), if the splitting of the semiconductor wafer and the cutting of the protective film are performed continuously by the same operation without interruption, regardless of the order, the splitting of the semiconductor wafer and the cutting of the protective film-forming film shall be considered to have been performed simultaneously.

[0223] The splitting of the semiconductor wafer 9 and the cutting of the protective film 13' can both be performed by known methods, depending on the order in which they are carried out.

[0224] For example, by various dicing methods such as blade dicing using a blade, laser dicing using laser light irradiation, or water dicing by spraying water containing an abrasive, the semiconductor wafer 9 and the protective film 13' can be cut simultaneously. Furthermore, by performing a so-called expansion, which involves pulling both the semiconductor wafer 9, which has a modified layer formed by stealth dicing (registered trademark) and has not been divided, and the protective film 13' in a direction parallel to their surfaces, the semiconductor wafer 9 can be divided and the protective film 13' can be cut simultaneously. Such expansion is preferably performed at low temperatures such as -20 to 5°C.

[0225] Stealth dicing (registered trademark) is a method described below. First, a location to be divided is set within the semiconductor wafer, and a laser beam is irradiated to focus on this location, thereby forming a modified layer within the semiconductor wafer. Unlike other parts of the semiconductor wafer, the modified layer is altered by the laser beam irradiation and has weakened strength. Therefore, when force is applied to the semiconductor wafer, cracks extending in both directions of the semiconductor wafer are generated in the modified layer inside the semiconductor wafer, becoming the starting point for the division of the semiconductor wafer. Next, force is applied to the semiconductor wafer to divide it at the location of the modified layer, and a semiconductor chip is manufactured.

[0226] As explained above, when a protective film-forming film 13 is used in which the content of filler (D) relative to the total mass of the protective film-forming film is 50% by mass or more, the protective film 130' on the semiconductor wafer 901' with the protective film has high protective performance and a high protective effect on the semiconductor chip 90. For example, chipping is suppressed on the semiconductor chip 913' with the protective film.

[0227] <Pickup Process> After the processing step of manufacturing method (1), in the pickup step, as shown in Figure 4(e), the semiconductor chip 913' with the protective film is picked up by pulling it away from the support sheet 10. In the pickup process of manufacturing method (1), delamination occurs between the second surface 130b' of the protective film 130' in the semiconductor chip 913' with the protective film and the first surface 12a of the adhesive layer 12 in the support sheet 10.

[0228] The semiconductor chip 913' with the protective film can be picked up by known methods. For example, in the manufacturing method (1), the semiconductor chip 913' with a protective film can be picked up by pushing it from the side of the support sheet 10 through the support sheet 10 (interposed) using pins. In FIG. 4(e), further, a case where the semiconductor chip 913' with a protective film is pulled in the direction of arrow P using separation means 7 such as a vacuum collet is shown.

[0229] After the pickup step of the manufacturing method (1), for example, the protruding electrodes in the picked-up semiconductor chip 913' with a protective film are flip-chip connected to the circuit surface of the substrate, whereby the semiconductor chip 913' with a protective film is bonded to the circuit surface (in this specification, it may be referred to as the "bonding step"). The protruding electrodes are provided on the circuit surface 90a of the semiconductor chip 90 in the semiconductor chip 913' with a protective film. In the bonding step, for example, the protruding electrodes in the semiconductor chip 913' with a protective film are brought into contact with connection pads provided on the circuit surface of the substrate, and the protruding electrodes and the connection pads on the circuit surface are electrically connected, whereby flip-chip connection can be achieved. The bonding of the semiconductor chip 913' with a protective film to the circuit surface can be performed by a known method.

[0230] After the bonding step, using the substrate provided with the semiconductor chip 913' with a protective film, hereinafter, a semiconductor package can be manufactured according to a known method, and by using this semiconductor package, a target semiconductor device can be manufactured.

[0231] So far, as the manufacturing method (1), the manufacturing method of a semiconductor device when using a composite sheet for forming a protective film has been described. However, even if a protective film forming film that does not constitute a composite sheet for forming a protective film is used instead of the composite sheet for forming a protective film, a semiconductor device can be manufactured. FIG. 5 is a cross-sectional view for schematically explaining an example of a manufacturing method (which may be referred to as "manufacturing method (2)" in this specification) when using a protective film forming film that does not constitute a composite sheet for forming a protective film in the manufacturing method of the semiconductor device of the present embodiment. Here, the case of using the protective film forming film 13 shown in FIG. 1 will be described.

[0232] <<Manufacturing method (2)>> <Laminating step> In the laminating step of the manufacturing method (2), as shown in FIG. 5(a), a protective film forming film 13 that does not constitute the composite sheet for forming a protective film, more specifically, the protective film forming film 13 from which the first release film 151 has been removed, is laminated on the back surface 9b of the semiconductor wafer 9 to produce a semiconductor wafer 901 with a protective film forming film. This step is the same as the laminating step of the manufacturing method (1), except that instead of the protective film forming film 13 that constitutes the composite sheet 101 for forming a protective film, that is, the protective film forming film 13 provided with the support sheet 10, a protective film forming film 13 provided with the second release film 152 is used.

[0233] The protective film forming film 13 may be cut into a circular shape having the same diameter as the semiconductor wafer 9 or a diameter 1 to 10 mm smaller than the diameter of the wafer before being laminated on the back surface 9b of the semiconductor wafer 9. By doing so, the workability in the laminating step and the workability of removing the second release film 152 described later are improved.

[0234] Also in the manufacturing method (2), since the heat generation start temperature of the test piece produced from the protective film forming film 13 in the above-described DSC is 160°C or higher, in the laminating step, the adhesiveness of the protective film forming film 13 to the semiconductor wafer 9 is good. For example, even when using the protective film forming film 13 stored at room temperature, the adhesiveness of the protective film forming film 13 to the semiconductor wafer 9 is good, and thereby the protection performance of the semiconductor chip by the protective film is also high.

[0235] <Thermosetting step> In the manufacturing method (2), after the bonding step, the thermal curing step involves thermal curing the protective film-forming film 13 in the semiconductor wafer 901 with the protective film-forming film to form a protective film 13' as shown in Figure 4(b). As a result, the semiconductor wafer 901 with the protective film-forming film becomes a semiconductor wafer 901' with a protective film. This process is the same as the thermosetting process in manufacturing method (1), except that instead of using a semiconductor wafer 9 equipped with a composite sheet 101 for forming a protective film, a semiconductor wafer 9 equipped with a laminate of a protective film forming film 13 and a second release film 152 is used.

[0236] In manufacturing method (2), as described above, if the protective film forming film 13 is one in which the proportion of filler (D) content relative to the total mass of the protective film forming film is 50% by mass or more, then in the semiconductor wafer 901' with the protective film, the protective film 13' has high protective performance and a high protective effect on the semiconductor wafer 9.

[0237] In manufacturing method (2), as described above, if a protective film forming film 13 is used in which the ratio of the filler (D) content to the total mass of the protective film forming film is 65% by mass or less, the effect of suppressing warping in the semiconductor wafer 901' with the protective film is enhanced.

[0238] <Printing process> In the printing step following the thermosetting step of manufacturing method (2), as shown in Figure 5(c), the second release film 152 is removed from the semiconductor wafer 901' with the protective film, and laser printing is performed on the newly exposed surface, i.e., the second surface 13b' of the protective film 13', by irradiating it with laser light R. The semiconductor wafer 901' with the protective film after laser printing is the same as the semiconductor wafer 901' with the protective film after laser printing in manufacturing method (1). In this process, laser printing can be performed on the protective film 13' in the same manner as in the printing step of manufacturing method (1).

[0239] <Dicing sheet application process> After the printing step in manufacturing method (2), as shown in Figure 5(d), a dicing sheet 80 is attached to the second surface 13b' of the protective film 13' in the semiconductor wafer 901' with the protective film. The dicing sheet 80 comprises a base material 81 and an adhesive layer 82 provided on one side thereof. In this step, the side of the adhesive layer 82 opposite to the base material 81 side (sometimes referred to as the "first surface" in this specification) 82a is attached to the second surface 13b' of the protective film 13'. The first surface 82a of the adhesive layer 82 is the same as the first surface 80a of the dicing sheet 80. Thus, the manufacturing method (2) includes a dicing sheet application step between the printing step and the processing step, in which a dicing sheet is applied to the side of the protective film in the semiconductor wafer with the protective film that is opposite to the semiconductor wafer side.

[0240] The dicing sheet 80 may have a similar configuration to the support sheet 10 in the protective film-forming composite sheet 101. Here, the case using dicing sheet 80 is shown, but in manufacturing method (2), other known dicing sheets besides dicing sheet 80 may be used, such as a dicing sheet made only of a base material.

[0241] The dicing sheet 80 can be attached to the protective film 13' by a known method, for example, in the same way as when the protective film-forming composite sheet 101 is attached to the semiconductor wafer 9 in the attachment step of manufacturing method (1).

[0242] In manufacturing method (2), the processing step, pickup step, and bonding step can be carried out in the same manner as in manufacturing method (1), except that, from the dicing sheet attachment step onward, a semiconductor wafer 901' with a protective film equipped with a dicing sheet 80 is used instead of the semiconductor wafer 901' with a protective film equipped with a support sheet 10 as described above, and the target semiconductor device can be manufactured.

[0243] <Processing process> For example, in the processing step following the printing step (dicing sheet attachment step) of manufacturing method (2), as shown in Figure 5(e), the semiconductor wafer 9 is divided into semiconductor chips 90 on the dicing sheet 80, and the protective film 13' is cut along the divided portion of the semiconductor wafer 9 to produce a semiconductor chip 913' with a protective film. The semiconductor chip 913' with a protective film obtained in this way is the same as the semiconductor chip 913' with a protective film in manufacturing method (1). In the processing step of manufacturing method (2), a group of semiconductor chips 903 with a protective film is produced, in which multiple semiconductor chips 913' with protective films are aligned and fixed on the dicing sheet 80 together with the semiconductor chip 913' with a protective film.

[0244] In manufacturing method (2), as described above, when a protective film forming film 13 is used in which the content of filler (D) relative to the total mass of the protective film forming film is 50% by mass or more, the protective film 130' on the semiconductor wafer 901' with the protective film has high protective performance and a high protective effect on the semiconductor chip 90. For example, chipping is suppressed on the semiconductor chip 913' with the protective film.

[0245] <Pickup Process> For example, after the processing step in manufacturing method (2), in the pickup step, as shown in Figure 5(f), the semiconductor chip 913' with the protective film is picked up by separating it from the dicing sheet 80. In the pickup step of manufacturing method (2), delamination occurs between the second surface 130b' of the protective film 130' in the semiconductor chip 913' with the protective film and the first surface 82a of the adhesive layer 82 in the dicing sheet 80.

[0246] The semiconductor chip 913' with a protective film picked up in the pickup process of the manufacturing method (2) is the same as the semiconductor chip 913' with a protective film picked up in the pickup process of the manufacturing method (1). Therefore, each subsequent process such as the bonding process in the manufacturing method (2) is the same as each process such as the bonding process in the manufacturing method (1), and a target semiconductor device can be manufactured as in the case of the manufacturing method (1).

[0247] <<Modification Example of Manufacturing Method of Semiconductor Device>> The manufacturing method of the semiconductor device of the present embodiment may have other processes that do not fall into any of the above-described sticking process, thermosetting process, printing process, dicing sheet sticking process, processing process, pickup process, and bonding process, as long as the effects of the present invention are not impaired. The other processes can be arbitrarily selected according to the purpose and are not particularly limited. The timing of performing the other processes can be appropriately selected according to the content of the other processes.

[0248] As an example of the other processes in the manufacturing method of the semiconductor device, there are a back grind tape sticking process of sticking a back grind tape to the back surface of the semiconductor wafer before the sticking process, and a back grind tape removing process of removing the back grind tape from the back surface of the semiconductor wafer after the back grind tape sticking process and before the sticking process. The back grind tape may be a known one, and the sticking of the back grind tape to the back surface of the semiconductor wafer and the removal from the back surface of the semiconductor wafer can be performed by known methods.

[0249] In this specification, the description of a mere "sticking process" means the process of sticking the above-described protective film forming film or the protective film forming film in the protective film forming composite sheet, which does not fall into either the "dicing sheet sticking process" or the "back grind tape sticking process", to the back surface of the semiconductor wafer.

[0250] Up to this point, we have described the case in which the protective film-forming composite sheet 101 shown in Figure 2 is used as the manufacturing method (1) above. However, in the manufacturing method of the semiconductor device of this embodiment, other protective film-forming composite sheets, such as the protective film-forming composite sheet 102 shown in Figure 3, may also be used. When using the aforementioned other protective film-forming composite sheet, the method for manufacturing the semiconductor device of this embodiment may include the aforementioned other steps, which may be performed at any given time, based on the differences in the configuration between the aforementioned other protective film-forming composite sheet and the protective film-forming composite sheet 101 shown in Figure 2. [Examples]

[0251] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below.

[0252] <Raw materials for resin manufacturing> The full names of the resin manufacturing raw materials, which are abbreviated in this example and comparative example, are shown below. BA: n-butyl acrylate MA: Methyl acrylate GMA: Glycidyl methacrylate HEA: 2-hydroxyethyl acrylate

[0253] <Raw materials for manufacturing protective film-forming compositions> The raw materials used in the production of the protective film-forming composition are listed below. [Polymer component (A)] (A)-1: Acrylic polymer obtained by copolymerizing BA (10 parts by mass), MA (70 parts by mass), GMA (5 parts by mass), and HEA (15 parts by mass) (weight-average molecular weight 400,000, glass transition temperature -1°C) [Epoxy resin (B1)] (B1)-1: Liquid bisphenol A type epoxy resin (Mitsubishi Chemical Corporation "jER828", epoxy equivalent 184~194 g / eq) (B1)-2: Solid bisphenol A type epoxy resin (Mitsubishi Chemical Corporation "jER1055", epoxy equivalent 800-900 g / eq) (B1)-3: Dicyclopentadiene type epoxy resin (DIC Corporation's "Epiclon HP-7200HH", epoxy equivalent 274-284 g / eq) [Thermosetting agent (B2)] (B2)-1: Dicyandiamide (thermally active latent epoxy resin curing agent, "DICY7" manufactured by Mitsubishi Chemical Corporation) [Curing accelerator (C)] (C)-1:2-phenyl-4-methyl-5-hydroxymethylimidazole (manufactured by Shikoku Chemicals Co., Ltd. as "Curesol (registered trademark) 2P4MHZ-PW") (C)-2: Imidazole-based curing accelerator (a 1:1 mixture of 1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 6-2-(2-methyl-1H-imidazole-1-yl)ethyl-1,3,5-triazine-2,4-diamine, manufactured by Shikoku Chemicals Co., Ltd., "Curesol (registered trademark) 2MAOK-PW") (C)-3:2-Heptadecylimidazole (Shikoku Chemicals Co., Ltd. "Curezol (registered trademark) C17Z") (C)-4:2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemicals Co., Ltd. "Curesol (registered trademark) 2PHZ-PW") [Filling material (D)] (D)-1: Silica filler (SC2050MA, manufactured by Admatex, spherical silica filler surface-modified with epoxy compounds, average particle size 0.5 μm) [Coupling agent (E)] (E)-1:3-Glycidoxypropyltrimethoxysilane (silane coupling agent, Shin-Etsu Silicone Co., Ltd. "KBM403", methoxy equivalent 12.7 mmol / g, molecular weight 236.3) [Coloring agent (I)] (I)-1: Organic black pigment (Dainichi Seika Kogyo Co., Ltd. "6377 Black")

[0254] [Example 1] <<Manufacturing of protective film-forming film>> <Manufacturing of protective film-forming composition (III)> Polymer component (A)-1 (18.45 parts by mass), epoxy resin (B1)-1 (11.07 parts by mass), epoxy resin (B1)-2 (1.85 parts by mass), epoxy resin (B1)-3 (5.54 parts by mass), thermosetting agent (B2)-1 (0.37 parts by mass), curing accelerator (C)-1 (0.37 parts by mass), filler (D)-1 (59.04 parts by mass), coupling agent (E)-1 (0.37 parts by mass), and coloring agent (I)-1 (2.95 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting protective film-forming composition (III)-1 in which the total concentration of all components other than the solvent was 50% by mass. The amounts of components other than methyl ethyl ketone shown here are all amounts of the target product excluding the solvent.

[0255] <Manufacturing of protective film-forming films> A release film (second release film, Lintec Corporation's "SP-PET502150", 50 μm thick) made of polyethylene terephthalate film, in which one side was treated with silicone for release, was used. The protective film-forming composition (III)-1 obtained above was applied to the release-treated surface, and the film was dried at 100°C for 2 minutes to produce a thermosetting protective film-forming film with a thickness of 25 μm.

[0256] Furthermore, a protective film-forming film with a release film was manufactured by laminating the release-treated surface of a release film (first release film, Lintec Corporation's "SP-PET381031", thickness 38 μm) to the exposed surface of the obtained protective film-forming film that does not have a second release film, under the conditions of a lamination speed of 2 m / min, a lamination temperature of 60°C, and a lamination pressure of 0.5 MPa, thereby comprising a protective film-forming film, a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film.

[0257] <<Evaluation of protective film-forming film>> <Measurement of the temperature at which heat generation begins> Using the multiple protective film-forming films with release films obtained above, the exposed surfaces of the protective film-forming films were sequentially bonded together while removing the first or second release films, thereby creating a laminate in which the second release film, multiple protective film-forming films, and the second release film were stacked in this order. Then, sections were cut out from this laminate. Next, the two outermost second release films were removed from this section, and the resulting specimen was used as the test piece. The mass of this test piece was approximately 5 g. Next, using a differential scanning calorimeter ("DSC-600" manufactured by Hitachi High-Tech Science Corporation), the test specimen was heated from 23°C to 300°C at a heating rate of 10°C / min using the DSC method, and the exothermic onset temperature was measured. The results are shown in Table 1.

[0258] <Evaluation of storage stability (adhesion) at room temperature> The protective film with release film obtained above was stored in air at a temperature of 23°C for 30 days. Next, using a tape laminator (Lintec RAD-3600F / 12), the protective film-forming film with a release film, which had been stored, was applied to the #2000 polished surface of a 12-inch silicon wafer (300 μm thick) under the conditions of a lamination speed of 50 mm / s, a roller temperature of 60°C, a table temperature of 80°C, and a lamination pressure of 0.25 MPa, while removing one of the release films (first release film). In this way, a silicon wafer with a protective film-forming film and a release film was fabricated, in which the release film (second release film), the protective film-forming film, and the silicon wafer were laminated in this order in the thickness direction.

[0259] Next, the release film was peeled off the silicon wafer with the protective film attached. At this time, the release film was peeled off the protective film so that the surfaces that had been in contact with each other formed a 180° angle (180° peeling was performed). Then, the adhesion state (adhesion) of the protective film to the silicon wafer was visually observed, and the storage stability of the protective film at room temperature was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: The protective film does not lift away from the silicon wafer at all, the protective film adheres tightly to the silicon wafer, and the protective film has high storage stability at room temperature. B: Air bubbles are present between a portion of the silicon wafer near the outer edge and the protective film, resulting in lower storage stability of the protective film at room temperature compared to A. C: The protective film is peeling off the silicon wafer along with the release film, indicating poor storage stability of the protective film at room temperature.

[0260] <Evaluation of the effect of suppressing warpage in silicon wafers with protective coatings> Using the same method as when evaluating the storage stability (adhesion) of the protective film-forming film at room temperature as described above, a silicon wafer with a protective film-forming film and a release film was fabricated by attaching the protective film-forming film obtained above to the #2000 polished surface of a 12-inch silicon wafer (300 μm thick). Next, after peeling off the release film from the silicon wafer with the protective film, the silicon wafer with the protective film was placed inside an oven and heated at 130°C for 2 hours to heat-cur the protective film, thereby producing a silicon wafer with a protective film.

[0261] Next, the obtained silicon wafer with protective coating was removed from the oven, cooled at room temperature, and then placed on the flat surface of the table. At this time, the silicon wafer within the silicon wafer with protective coating was positioned facing the flat surface of the table. The side of the silicon wafer within the silicon wafer with protective coating becomes convex if warping occurs in the silicon wafer with protective coating. The distance between the flat surface of the table and the silicon wafer with protective coating was measured at three arbitrary points on the outer circumference of the silicon wafer with protective coating, and the average value was adopted as the amount of warping of the silicon wafer with protective coating. Furthermore, the effect of suppressing warping in the silicon wafer with protective coating was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: The amount of warping is 0 mm, indicating that warping is suppressed. B: The amount of warping is greater than 0 mm and less than or equal to 2 mm, and the warping suppression effect is inferior to A, but the protective film-forming film can be used in practical applications. C: The amount of warping exceeds 2 mm, resulting in a low warping suppression effect, and the protective film cannot be used for practical purposes. Here, the fact that the protective film-forming film is usable in practical applications means that, after the protective film-forming film has been heat-cured (after the protective film has been formed), it is possible to carry out normal processes without any problems, such as attaching a dicing sheet and dicing the semiconductor wafer with the protective film.

[0262] <Evaluation of the chipping suppression effect of silicone tips with protective coatings> Using the silicon wafers with protective films prepared in the evaluation of the warping suppression effect on silicon wafers with protective films described above, the adhesive side of a dicing tape (Lintec Corporation's "Adwill D-686H") was attached to the exposed side of the protective film (the side opposite to the silicon wafer) using a tape mounter (Lintec Corporation's "Adwill RAD-2510F / 12"). The attachment conditions were: attachment speed 30 mm / s, roller temperature 23°C, table temperature 23°C, and attachment pressure 0.25 MPa. Next, using a dicing device (DISCO "DFD6361"), the silicon wafer with a protective film was diced to divide the silicon wafer into silicon chips measuring 5 mm x 5 mm, and the protective film was cut to the same size as the silicon chips, thereby producing a large number of silicon chips with protective films. At this time, the dicing blade (DISCO "Z05-SD2000-N1-90 CC") was set to a travel speed of 30 mm / sec, a rotation speed of 45,000 rpm, and a height of 65 μm. Next, these protective-coated silicon chips were transferred from the dicing sheet to an adhesive sheet (Lintec's "Adwill D-210"). Ten of these protective-coated silicon chips were then observed using a digital microscope to determine the maximum value of chipping (cracks or chips in the silicon chip). Based on this maximum value, the chipping suppression effect of the protective-coated silicon chips was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: The maximum chipping size is 20 μm or less, indicating a high chipping suppression effect. B: The maximum chipping size is between 20 μm and 50 μm, which is inferior to A, but chipping is suppressed. C: The maximum chipping size exceeds 50 μm, indicating that chipping is not suppressed.

[0263] <<Manufacturing and Evaluation of Protective Film Forming Films>> [Examples 2-6, Comparative Examples 1-2] The protective film-forming film was manufactured and evaluated using the same method as in Example 1, except that the types of components were changed so that the components and their contents of the protective film-forming film were as shown in Table 1 or Table 2. The results are shown in Table 1 or Table 2.

[0264] [Table 1]

[0265] [Table 2]

[0266] As is clear from the results above, in Examples 1 to 6, the adhesion of the protective film to the silicon wafer was good, and it was confirmed that the protective film had high storage stability at room temperature. In Examples 1 to 6, the exothermic start temperature of the test specimens measured by DSC was 170.6°C or higher, which was sufficiently high.

[0267] Furthermore, in Examples 1 to 6, both the effect of suppressing warping in silicon wafers with protective films and the effect of suppressing chipping in silicon chips with protective films were good, indicating that the protective film-forming film had excellent properties.

[0268] In contrast, in Comparative Examples 1 and 2, the adhesiveness of the protective film-forming film to the silicon wafer was poor, and the storage stability of the protective film-forming film at room temperature was poor. In particular, in Comparative Example 2, the storage stability of the protective film-forming film at room temperature was low. In Comparative Examples 1 and 2, the exothermic start temperature of the test specimens by the DSC method was 149.3°C or lower, which was insufficient. In Comparative Examples 1 and 2, the protective film-forming film could not be properly attached to the silicon wafer, therefore, the effect of suppressing warping on silicon wafers with protective films and the effect of suppressing chipping on silicon chips with protective films were not evaluated. [Industrial applicability]

[0269] This invention can be used in the manufacture of semiconductor devices. [Explanation of Symbols]

[0270] 10...Support sheet, 10a...One side of the support sheet (first side), 11...Base material, 12. Adhesive layer, 13,23...Protective film forming film, 13a,23a...One side (first side) of the protective film forming film, 13'... Protective film, 13b'... Support sheet side of the protective film (second side), 130'... Protective film after cutting, 101, 102... Composite sheets for forming protective films, 80 dicing sheets, 9... Semiconductor wafer, 9a... Circuit side of semiconductor wafer, 9b... Back side of semiconductor wafer, 90... Semiconductor chips, 913'... Semiconductor chip with protective film

Claims

1. A thermosetting protective film, The protective film-forming film contains a filler (D) and an organic black pigment. The filler (D) is either an inorganic filler or a surface modifier thereof, or both, and the inorganic filler is one or more selected from the group consisting of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride. In the protective film forming film, the ratio of the content of the filler (D) to the total mass of the protective film forming film is 40% by mass or more. A protective film-forming film in which, when a test specimen of the protective film-forming film is heated from 23°C to 300°C at a heating rate of 10°C / min, the exothermic onset temperature is 170°C or higher, as determined by differential scanning calorimetry.

2. The protective film forming film according to Claim 1, wherein the ratio of the content of the filler (D) to the total mass of the protective film forming film is 63% by mass or less.

3. The protective film forming film according to claim 1 or 2, wherein the ratio of the content of the filler (D) to the total mass of the protective film forming film is 50% by mass or more.

4. It comprises a support sheet and a protective film-forming film provided on one surface of the support sheet, A composite sheet for forming a protective film, wherein the protective film forming film is the protective film forming film according to any one of claims 1 to 3.

5. A method for manufacturing a semiconductor device, The manufacturing method includes a bonding step of bonding one side of the protective film forming film described in any one of claims 1 to 3, or the exposed side of the protective film forming film in the protective film forming composite sheet described in claim 4, to the back surface of a semiconductor wafer. After the aforementioned bonding step, a heat curing step is performed to heat-cur the protective film-forming film to form a protective film, After the heat curing step, if the protective film-forming composite sheet is used, a printing step is performed in which laser printing is performed on the side of the protective film on the support sheet side of the protective film in the protective film-forming composite sheet, and if the protective film-forming film that does not constitute the protective film-forming composite sheet is used, laser printing is performed on the other side of the protective film. If the protective film-forming composite sheet is used after the printing step, the semiconductor wafer is divided into semiconductor chips on the support sheet in the protective film-forming composite sheet, and the protective film is cut along the division points of the semiconductor wafer. If the protective film-forming film, which is not part of the protective film-forming composite sheet, is used, a dicing sheet is attached to the other side of the protective film, and then the semiconductor wafer is divided into semiconductor chips on the dicing sheet, and the protective film is cut along the division points of the semiconductor wafer. This process produces a semiconductor chip with a protective film comprising the semiconductor chip and the cut protective film provided on the back surface of the semiconductor chip. A method for manufacturing a semiconductor device, comprising: a pickup step after the processing step, of picking up the semiconductor chip with the protective film by separating it from the dicing sheet or support sheet.

6. A method for manufacturing a semiconductor device according to claim 5, wherein the protective film-forming composite sheet, or the protective film-forming film that does not constitute the protective film-forming composite sheet, is stored at room temperature for 30 days before being used in the bonding step.

7. A method for manufacturing a semiconductor device using a thermosetting protective film-forming film or a composite sheet for forming a protective film, By differential scanning calorimetry, when a test specimen of the protective film-forming film was heated from 23°C to 300°C at a heating rate of 10°C / min, the exothermic onset temperature was 170°C or higher. The protective film-forming composite sheet comprises a support sheet and the protective film-forming film provided on one surface of the support sheet. The manufacturing method includes a bonding step of bonding one side of the protective film-forming film, or the exposed side of the protective film-forming film in the protective film-forming composite sheet, to the back surface of a semiconductor wafer. After the aforementioned bonding step, a heat curing step is performed to heat-cur the protective film-forming film to form a protective film, After the heat curing step, if the protective film-forming composite sheet is used, a printing step is performed in which laser printing is performed on the side of the protective film on the support sheet side of the protective film in the protective film-forming composite sheet, and if the protective film-forming film that does not constitute the protective film-forming composite sheet is used, laser printing is performed on the other side of the protective film. If the protective film-forming composite sheet is used after the printing step, the semiconductor wafer is divided into semiconductor chips on the support sheet in the protective film-forming composite sheet, and the protective film is cut along the division points of the semiconductor wafer. If the protective film-forming film, which is not part of the protective film-forming composite sheet, is used, a dicing sheet is attached to the other side of the protective film, and then the semiconductor wafer is divided into semiconductor chips on the dicing sheet, and the protective film is cut along the division points of the semiconductor wafer. This process produces a semiconductor chip with a protective film comprising the semiconductor chip and the cut protective film provided on the back surface of the semiconductor chip. The process includes a pickup step, in which the semiconductor chip with the protective film is picked up by separating it from the dicing sheet or support sheet after the processing step, A method for manufacturing a semiconductor device, comprising storing the composite sheet for forming a protective film, or the protective film-forming film that does not constitute the composite sheet for forming a protective film, at room temperature for 30 days before using it in the bonding step.

8. A protective film-forming film is used to be attached to the back surface of a semiconductor wafer opposite to the circuit surface, and to form a protective film on the back surface of a semiconductor chip obtained by dividing the semiconductor wafer, Use of a protective film-forming film, wherein the protective film-forming film is the protective film-forming film described in any one of claims 1 to 3.

9. The use of the protective film forming film according to claim 8, wherein the protective film forming film is attached to the back surface of the semiconductor wafer after being stored at room temperature for 30 days.

10. Use of a thermosetting protective film-forming film for attaching to the back surface of a semiconductor wafer opposite to the circuit surface, and for forming a protective film on the back surface of a semiconductor chip obtained by dividing the semiconductor wafer, By differential scanning calorimetry, when a test specimen of the protective film-forming film was heated from 23°C to 300°C at a heating rate of 10°C / min, the exothermic onset temperature was 170°C or higher. Use of the protective film-forming film, wherein the protective film-forming film is attached to the back surface of the semiconductor wafer after being stored at room temperature for 30 days.

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